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It’s been a mild February here in Columbus. All the same, most of us are ready for March to blow in with its promise of more daylight, budding flowers, and spring training games on the radio. So why do we have to wait an extra day this year for the festivities to begin?
The easy answer is this. A day is 24 x 60 x 60 = 86,400 seconds long. But a year, measured from equinox to equinox, is 31,556,926 seconds long. Divide the second number by the first and you get (approximately) 365.2422. In order to keep our calendar solstices and equinoxes lined up with real astronomical events, we have to add approximately one day every four years. Done.
(It should come as no great surprise, by the way, that these two events, the length of the day and the length of the year, don’t match up precisely. Actually, we’re pretty fortunate that their remainder comes out so close to an even 1/4. Imagine the difficulty we’d have if the fraction was more like 3/7 or something really ugly like 113/197, so that 113 of every 197 years would be a leap year. How do we learn that rule?)
But there is a much deeper answer than the mathematical one, and it has to do with the structure of the universe itself. We live in a universe where the laws of physics work.
There are two major periodic events we use to time our lives, the day and the year. Why these two? Because both are amazingly regular.
You’ll sometimes see reports of “leap seconds” required to keep the length of the day in time with our best clocks. It is true that the Earth is slowing down due to tidal forces from both the Moon and the Sun. All in all, the Earth loses something like half a second a year, requiring the addition of “leap seconds” every so often.
Don’t lose sight, though, of just how astoundingly constant the rotation of the Earth is. Consider that were you standing at sea level on the equator you’d be whipping around at over 1000 miles per hour. Imagine trying to design a machine that spun at that rate for an entire year and yet kept its speed constant to within one second!
What about the year itself? Well, the Sun’s mass determines the Earth’s orbital period, and we know via E=mc2 that the Sun is losing mass. How much mass? Oh, just four billion kilograms every second! However, the Sun is so enormous that this amount of mass loss is completely insignificant to the Sun. In fact, calculating the increase in the length of the Earth’s year due to this loss, we find that the year has lengthened by about half a second in around 1250 years. Again, consider how remarkable this is: a planet moving in its orbit over 67,000 miles per hour has kept its same rate of motion to within half a second for over a thousand years!
But to me, there’s something far more astounding. Yes, the Earth’s rotation is an impressive clock, and its revolution an even better one. For almost all of human existence these clocks were far more precise than anything the finest watchmaker could fashion. That finally changed, though, in 1955, when a person with a good explanation built the world’s first atomic clock. For the first time on our planet (for all we know, the first time in the history of the universe), there existed a device that kept better time than the Earth itself.
Think about that for a moment. For thousands of years, we humans struggled to make a clock as good as the Earth. Today, thanks to people with good explanations of how the world works, we have clocks that not only match the Earth’s accuracy, but so far exceed it that we can actually detect the Earth’s own chronological imperfections. Today’s best clocks lose one second in 15 million years, and future clocks might lose one second in ten billion turns of the Earth around the Sun.
Through good explanations of how the world works, humans have built timepieces that far exceed anything nature has cooked up. So good are the clocks we’ve built that we can measure and correct for even the tiny discrepancies we’ve discovered in the motion of our clockwork Earth on its journey through space. As you watch February turn into March, consider how regular are the patterns of days and years, and consider too just how amazing it is to live in the time when we humans can do even better.
Homer Simpson once said of the USA Today that it is the only newspaper that isn’t afraid to tell the truth – that everything is just fine!
I’m a little bit afraid that I’m becoming a Homer. A few years ago I became interested in the idea of “peak oil.” At the time I was working on an article about petroleum and I read a book by David Goodstein, of Mechanical Universe fame (ok, fame for me. I’ll admit it’s a little weird that I know more physicists by name than rock stars).
Anyway, Goodstein’s book, Out of Gas, is pretty grim regarding the future. Goodstein and others say that oil, as a finite resource, must eventually become scarce. When demand outstrips supply, oil will become too expensive to use, and essentially all our technology will grind to a halt.
At the same time, I read another book, skeptical of the idea of peak oil. This book was by a free-market economist named Peter Huber and a physicist named Mark Mills. It was called The Bottomless Well. In the book, the authors made the argument that we will never run out of energy because energy begets energy. Sounded like a pretty crazy idea at the time, and I mostly discounted what they had to say.
But even then something about their optimism regarding human ingenuity struck me as a powerful idea. I guess it stayed with me more than I knew, because as I read Beginning of Infinity, I recalled this strange energy book I’d read earlier. Recently I returned to The Bottomless Well and read it again.
Like Deutsch in BoI, the authors of The Bottomless Well present some deeply counter-intuitive ideas. The first is that energy is not what we’re after at all. Instead it’s order that we seek. In fact, we use up most of the energy we collect in transforming energy from less-ordered to more-ordered.
One great example is how we make and use electricity. There’s a commercial I’ve seen in which laptops and mp3 players are powered by gasoline. The reason this is silly isn’t that gasoline is polluting. It’s that gasoline lacks the order needed to operate things like laptops.
When we burn coal or oil to make electricity, we aren’t just transforming one kind of energy into another. The transformation process is never 100% efficient – far from it. When we transform energy we lose most of it, but we end up highly-ordered energy that we use to run laptops, lasers, and surgical robots. Much of The Bottomless Well is about how much energy we waste in creating order in the form of electricity. This waste is both necessary and good – the more energy we waste in this way, the more possibilities we create.
Another counter-intuitive idea is that energy efficiency is self-defeating. Consider the first computers. With their rooms full of vacuum tubes to perform even the simplest arithmetical tasks, they were amazingly inefficient. My laptop today is vastly more powerful and hugely more efficient than the most powerful computer on the planet sixty years ago. Yet it is just this efficiency, made possible by transistors and then integrated circuits, that has caused the total energy used by computers today to skyrocket. Efficiency doesn’t let us do less, it encourages us to do more. Therefore energy efficiency will always lead to more consumption, not less.
One of the most memorable parts of the book was the allusion to the coal problem in the early 1800s. Everyone knew that coal was a vastly superior fuel to wood, which in any case was dwindling away. But how to move the coal, heavy and bulky, from where it was found to where it was needed? In the end, through the invention of the coal-fired pump and the coal-fired steam locomotive, the coal moved itself. Energy begets more energy.
It’s a powerful, optimistic view of human potential that serves as a fine sequel to Deutsch’s book. As a dyed-in-the-wool liberal, I remain skeptical of the authors’ faith in the free market to find the best solution to every problem. But I also recognize that I still have lots to learn. An infinite amount, in fact.
Of course we’ll run out of oil someday. Problems are inevitable. But problems are also soluble. All evil results from a lack of knowledge. The answer to our problems isn’t to pull back. It’s to move forward, actively searching for more knowledge, more solutions, more sources of ever better energy. Of course those energy sources will be imperfect, and will lead to new problems. Problems are inevitable. But, with enough knowledge, problems are soluble.
Near the beginning of The Beginning of Infinity, David Deutsch writes, “One of the most remarkable things about science is the contrast between the enormous reach and power of our best theories and the precarious, local means by which we create them.” This remarkable thing first struck me when I read a book called The Universe written in 1966 by Isaac Asimov. Before reading this book, I had some vague notion that science had some sort of black box into which light went and out of which came all sorts of information. In Asimov’s book, for the first time, I recognized that every piece of knowledge we have is a prize that had to be won with imagination and hard work.
Lawrence Krauss’s new book A Universe From Nothing takes me down the same path I first traveled with The Universe. Krauss’s book is quite short, but doesn’t shy away from the thing that makes science so different from every other field. In science, it’s not just what you know, it’s how you know it. It’s how you got there, what were your methods, your tools, your approach. Beginning with Einstein’s update of Newton, Krauss takes us through the discovery of the Big Bang, the flatness of space, inflation, dark matter, and the surprising discovery of dark energy. It all hangs together so elegantly, and has the added benefit of serving as a logical sequel to The Universe.
One of the very best parts of the present book is Krauss’s contrast of two predictions. One he calls the best prediction in all of science. The other he calls the worst prediction in all of science. Amazingly, they both have to do with the same idea: virtual particles.
The best prediction is of the affect of virtual particles on a hydrogen atom. A hydrogen atom looks pretty simple; a single electron moving around a single proton. Yet the forces between these two charged particles didn’t come out right until virtual particles, particles that pop in and out of existence all the time between and near the proton and electron, are taken into account. When these affects are included, the answer matches experiment to within one part in a billion. That’s pretty good figuring, and is powerful evidence that scientists are on to something.
And yet, when virtual particles are included in the calculations of empty space, the result is wrong by 120 orders of magnitude, making this the worst prediction in the history of science (the same terrible prediction Leonard Susskind discussed in The Cosmic Landscape.)
Clearly there’s a lot we still don’t understand about virtual particles.
So why is there something rather than nothing? “Nothing”, it seems, is unstable. Given enough time, something like our universe appears inevitable. There’s also a nice discussion of why, when we consider gravitational as well as other forms, the total energy of the universe is in fact always zero. The universe is the ultimate free lunch. It’s just one of those things, like particle-antiparticle pairs, that happens from time to time. Given the levels of uncertainty we still have about the dark energy problem, quantum gravity, and so on, there’s certainly nothing like a proof that the universe emerged from nothing. However, as Krauss points out, just the fact that such an idea is now plausible is quite telling. There’s still lots more to learn, and of course that’s the best part.
One part of the book that I have to disagree with, though, is Krauss’s pessimism about the future, on at least two counts. First, Krauss says that in the far future cosmology will be impossible. All the galaxy clusters will have disappeared beyond the horizon, and even the glow of the cosmic background radiation will be too faint to detect over the light noise of the galaxy. Second, Krauss says that even farther in the future, life itself will become impossible as the universe becomes utterly dilute and void of useful energy.
As David Deutsch points out, this need not be so. Krauss’s vision is one in which knowledge plays no role. But Deutsch recognizes that knowledge is a fundamentally different, and transformative, thing. With the right knowledge, anything is within our grasp. Just as today we are not dependent upon cloudless skies to do astronomy, in the far future we may not be dependent on seeing through the “noise” of our own galaxy. And as we gain even more transformative ability, we may well discover new sources of evidence that today we don’t dream of. Given the history of science so far, it would be surprising were this not to happen.
The far future is also not so gloomy as Krauss suggests. Given enough knowledge, we may even find a way to harness dark energy. As the universe expands, dark energy expands with it, never growing dilute. This could become a truly infinite, inexaustible supply of energy, with which people (undoubtedly very different from the naked apes that first appeared on Earth billions or even trillions of years earlier) could become masters of the entire universe. Krauss doesn’t think such a people-centered universe could come about, or perhaps just doesn’t consider it. But as Deutsch shows us, we could choose to make it happen. It’s up to us.
I don’t have much to say about this book. Deutsch writes of the Copenhagen Interpretation that “It’s disparagement of plain criticism and reason as being ‘classical’ and therefore illegitimate, has given endless comfort to those who want to defy reason and embrace any number of rational modes of thought. Thus quantum theory – the deepest discovery of the physical sciences – has acquired a reputation for endorsing every mystical and occult doctrine ever proposed.”
You’ll find many of those mystical and occult doctrines championed by the heroes of How the Hippies Saved Physics. Sure, quantum encryption is pretty cool, and it was because the “hippies” of the title got it so wrong that others got it right. In my mind, that’s not a ringing endorsement of their methods. I would have liked the author to point out that things like ESP, clairvoyance, and telekinesis actually don’t work. One would think, given null result after null result, that the physicists profiled in this book would have eventually gotten the idea. But many of them are still championing the same flapdoodle even today.
Quantum mechanics is amazing enough without having to add mysticism and nonexistent forces to it. Don’t waste your time with this book.